受驱动耗散且空间关联的光-物质系统中的非厄米动力学
Non-Hermitian dynamics in a driven-dissipative and spatially correlated light-matter system
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中文总结 AI 辅助
本研究推导了受驱动耗散量子系统非厄米动力学的统一理论框架，通过$^{87}$Rb BEC的物质波衍射实验验证，揭示了相干驱动与耗散的相互作用及衰减速率随驱动增加而降低的特殊特征。
中文摘要 AI 辅助
量子力学教材中描述的纯量子态是理想表示，在真实系统中会因与环境的任何耗散连接而不可避免地劣化。本研究推导了一个统一理论框架，用于研究受驱动耗散量子系统的非厄米动力学，并通过与物质波衍射的实验数据对比对其进行验证。为突出耗散的作用，我们在光-物质相互作用的近共振 regime（区域）中进行对比，该区域微扰方法失效。研究表明，所开发的形式体系既支持精确模拟，又能基于模态分析进行直观解释。理论分析基于受驱动耗散系统的一般主方程描述，从中推导得出有效复势 $V_\mathrm{eff}(\Omega,\Delta)$，其依赖于光-物质相互作用的振幅和失谐等控制参数。实验上，我们利用周期性激发态工程驱动 $^{87}$Rb 玻色-爱因斯坦凝聚体（BEC）使其接近共振，将空间调制的 $V_{\rm eff}[\Omega,\Delta(x)]$ 映射到动量空间以进行精确量化。实验结果与主方程的数值模拟一致，证明了相干驱动与耗散之间的相互作用，具有一个特殊特征：衰减速率随驱动的增加而降低。随后，通过非厄米哈密顿量 $H_\mathrm{eff}=p^2/2m+V_\mathrm{eff}$ 的模态分析对这种动力学进行了解释，为该受驱动耗散系统提供了直观且定性的说明。
英文摘要
Pure quantum states, as described in quantum mechanics textbooks, are ideal representations inevitably deteriorated in real systems by any dissipative connection to the environment. In this work we derive a unified theoretical frame to study the non-Hermitian dynamics of a driven-dissipative quantum system and validate it by comparison to experimental data of matter-wave diffraction. To highlight the role of dissipation, we perform the comparison in a near-resonant regime of light-matter interaction, where perturbative approaches fail. Here, we show that the developed formalism enables both exact simulations and an intuitive interpretation based on modal analysis. The theoretical analysis is based on the general master equation description of driven-dissipative systems, from which we derive an effective complex potential $V_\mathrm{eff}(Ω,Δ)$ that depends on control parameters such as the amplitude and detuning of the light matter interaction. Experimentally, we drive a $^{87}$Rb BEC near resonance using periodic excited-state engineering, mapping the spatially modulated $V_{\rm eff}[Ω,Δ(x)]$ into momentum space for precise quantification. The experimental results agree with numerical simulations of the master equation and demonstrate the interplay between coherent drive and dissipation, with an exceptional signature: a reduced decay rate with increasing drive. Such dynamics is then interpreted by a modal analysis of the non-Hermitian Hamiltonian $H_\mathrm{eff}=p^2/2m+V_\mathrm{eff}$ which provide an intuitive and qualitative explanation for such driven-dissipative system.
